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RV4 metal cheek extensions

S

Sanch627

Member
Does anyone know if the older metal cowl extensions will fit newer cowls my kit is #4633, if they will work any idea where they could be found.
Chris RV 4 N1212R
 
DIY

I fabricated custom ones for an RV-3 repair job. A slip roller machine would have helped, but I was able to do it with hand tools. It did take two tries and quite a few shims to get the forward bulkhead to look good and match the cowl.
 
4 cheek extensions

Good point, will try 016 and use fiberglass ones as a mold, will give it a try.
Chris
RV 4 #4633
 
Too bad people that can use a English Wheel is becoming a lost art, wish I could do it. There was a video of a really old guy making a radial engine speed ring out of flat stock, it was amazing.
 
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I might suggest a 6061-0 or 3003 material and not 2024 as it will be quite hard to work. 025 would be less prone to damage.
 
Why?

I'm a true metal guy, and I can use an English wheel, also built my RV4. Metal extensions while are quite nice may be a tougher fit than the glass ones which are pretty robust. I had similar thoughts, but very pleased with the rigidity and fit of the fiberglass ones .
 
Yes, O condition to fabricate then heat treat, not a big deal with aluminum. A common practice during heavy checks.
 
blaplante said:
I fabricated custom ones for an RV-3 repair job. A slip roller machine would have helped, but I was able to do it with hand tools. It did take two tries and quite a few shims to get the forward bulkhead to look good and match the cowl.
Click to expand...

I should add that I now recall that getting them down to a point is pretty impossible in metal. So what I did was trimmed the end off at about 1" and made a 3D printed tip to finish off the point.

I did the work with .032" 2024-T3, and that was a bear. It was in the middle of a bunch of shortages and thinner stock wasn't available.
 
That's why I said it was a art. One that is being lost, in the thirties and forties all those complex curves on airplanes were done by hand.
 
Photos?

Anyone have any photos of the cheek extensions where they end at the cowl? I have seen one other and it looked great!

Mine seem to have a gap at the top. With a wood prop, I won't be flying in the rain, but it does look like a great rain catcher! I was thinking about glassing it in or making a cover plate of some sort. Any suggestions? That is not the best photo of it but I am sure you get the jest. It just looks crappy....
 

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Glass, glass, glass 👍

Sand a foam core to match the cowl. Three layers of glass are perfect because it is a curved cone. Put flanges turned inside, not out for classy appearance. Glue / poprivet fuse to flange sparingly.
Send email to [email protected] for pics.
 
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